Radiator cooling fan clutch



YosHlKAzu KuzE 3,221,721

RADIATOR COOLING FAN CLUTCH 3 Sheets-Sheet l Dec. 7, 1965 Filed July 28; 1964 m N E M Yoshi/auf Kaze Bufm/mwgw ATTORNEYS YosHlKAzU KuzE RADIATOR COOLING FAN CLUTCH Dec. 7, 1965 3 Sheets-Sheet 2 Filed July 28, 1964 INVENTOR yoslq KaZM Kz/Lze, Mm MW, @MM

l l. J Illu-i mm. f

ATTORNEYS` United States Patent 3,221,721 RADIATOR COOLING FAN CLUTCH Yoshikazu Kuze, 64 Chidori-cho, Chofu, Ota-ku, Tokyo Japan Filed July 28, 1964, Ser. No. 385,665 Claims priority, application Japan, Aug. 10, 1963,

38/ 42,321; June 23, 1964, 39/35,243

Claims. (Cl. 123-41.12)

The present invention is characterized in that it provides means whereby the cooling fan may be engaged and disengaged automatically in the relation between the ternperature of the cooling water of the engine and the rotational speed of the automobile engine.

In general practice of the automative field, driving of the cooling fan is not needed except in driving on the long upward slope and in low speed drive.

This is because for example when the automobile runs over 50 km./hr., sufficient cooling air is provided by movement of the automobile, so that there is no need for driving the cooling fan. v

Of course, the above condition should be corrected in the summer season and the winter season.

In high rotational speed of the engine, about 10% of the total output of the engine is consumed for driving the fan, so that there is much waste of fuel in the present radiator cooling system in which the cooling fan is continuously connected to the engine.

One of the objects of -this invention is to provide an apparatus in which the cooling fan runs idly while the cooling water of the engine is still cold after starting of the engine and when the temperature of the cooling water rises to normal operating temperature (about 80 C.) the fan is actuated by the action of the thermostat to prevent the temperature rise of water and when the water temperature is lowered the fan is caused to run idly by the action of the thermostat to promote the temperature rise of the water.

Another object of this invention is to obtain an apparatus in which the fan runs idly by the help of the centrifugal means which overcome the action of the thermostat when the speed of the automobile is over the predetermined value (assume the automobiles speed being 50 km./hr.).

A further object of this invention is to obtain an apparatus in which the drive of the fan is regulated by the action of the thermostat when the automobile is transferred to the low speed (for example less 50` km./hr.) from the high speed in which the fan is running idly.

Another object of this invention is to obtain an apparatus in which over heating of the engine may be prevented by driving the fan with overcoming of the centrifugal force mechanism by the action of the thermostat when the speed of the automobile is low, and even when the rotational speed of the engine is high in such cases as when the car drives on the long upward slope in low speed.

Still another object of this invention is to obtain an apparatus in which as the rotation of the fan attains the predetermined value (about 2,500 r.p.m.), the fan keeps the determined number of revolutions for preventing the loss of power even though the revolutions of the engine is increased further thereafter.

Other objects and advantages of the present invention will become apparent when the following detailed description is read in conjunction with the appended drawings, in which,

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention;

FIGS. 2 and 3 are the sectional views along the line X-X in FIG. 1 showing engaged and disengaged posi- 3,221,721 Patented' Dee. 7, 1965 ice'A tions, respectively, of the fan clutch in response to the water temperature;

FIGS. 4 and 5 are the sectional views along the line Y-Y in FIG. 1 showing engaged and disengaged positions, respectively, of the fan clutch in response to the centrifugal force;

FIG. 6 is a partly enlarged view of the weight actuated by the centrifugal force;

FIG. 7 is a sectional view of the weight actuated by the centrifugal force;

FIG. 8 shows the driving shaft of the water pump;

FIG. 9 shows the sliding block;

FIG. 10 is a perspective View of the elastic body; and

FIG. l1 is a longitudinal sectional view showing other embodiment of the present invention.

Referring to the drawings, 1 is a pulley to be rotated relative to the crank shaft at constant speed ratio, 2 is a driving shaft of the water pump. 3 is an impeller of the water pump. Boss 4 is pressed into said impeller 3 and engaged onto the end of the driving shaft 2. Wax type thermostat 5 is secured to the boss 4 by a stop ring 6 and O ring 7 and its heat sensible part 8 is exposed in the Water passage 9 of the water pump. Suction side 10 of the water pump is connected to the lower part of the radiator and the delivery side 11 thereof is opened to the water jacket of the engine. Connecting member 12 is xed to the driving shaft 2 by the key 13 and stop ring 14 and has the pulley 1 fixed therewith. 15 is the movable pin of the thermostat 5. 16 is a spring-receiving disc. 17 is a strong compression spring for determining the maximum revolution of the fan. One end of the push rod 18 is engaged with the elastic body 19 sealed closely in the driving shaft 2. 20 is a compression spring for pulling back said push rod 18. Sliding block 21 is mounted slidably in the radial direction of the driving shaft 2.

As shown in FIG. 9, the upper end of the sliding block 21 has a recess in which a roller 22 is inserted rotatably. Sliding block 21 is provided with a leg 23 accommodating in a radial hole in the driving shaft 2 and has a springreceiving pin 24 which projects from the sliding block 21 lin such a way that it is a right angle to the longitudinally axis of the roller 22. As shown in FIG. 8, the driving shaft 2 is provided the guiding groove 25 for the sliding block 21. Relief groove 26 of said spring-receiving pin 24 is formed in crosswise to said guiding groove 25. Fixed spring-receiving pin 27 is secured to the end of the side face of the driving shaft 2. Extension springs 28 are provided between spring-receiving pins 24, 27 and they have strength enough to prevent the radial outward flying out motion of the sliding block 21 including the roller 22 and spring-receiving pin 24 by the centrifugal force at the maximum rotation of the engine. The leg 23 of the sliding block 21 engages with the recess 29 of said elastic body 19. The stopper 30 of the elastic body 19 is secured by a stop ring. 31 is a water pump casing. 32, 33 are ball bearings. 34 is an oil seal. 35 is a stop ring. Disc 36 is rotatable on the water pump driving shaft 2 by the ball bearing 37. The cooling fan 38 and the cam ring 39 are secured to the disc 36. The roller 22 of the said sliding block 21 is engaged to this cam ring 39.

Free swingable weights 40, 40 are supported by pins 41, 41', said disc being fixed to the driving shaft 2. Sliding pins 42, 42' can slide in the holes drilled radially in the driving shaft 2 and their heads 43, 43 engage with the weights 40, 40 and the legs 44, 44 thereof engage with recesses 45, 45' of the elastic body 19. 46 is extension spring provided between Weights 40, 40 and 47, 47 are pins for supporting said spring at both ends thereof. 48, 48' are cam holes formed in the weights 40, 40

Extension spring 46 has strength enough to press down the sliding pins 42, 42, in radially outwardly through the weights 40, 40', until the number of revolutions of the engine reaches the predetermined value (for eX- ample 60 km./ hr. at top gear in summer season). When the spring-receiving pins 47, 47 are moved towards the supporting points 41, 41', the predetermined value of the number of revolutions of the engine is lowered progressively. Accordingly, as shown in FIG. 6, on the inner faces of the inclined cam groove three sets of recesses 49, 49', 50, 50', 51, 51 are arranged suitably spaced and recesses 49, 49' are defined for the summer seasOn, 50, 50 are defined for the spring and autumn season, 51, 51' are defined for the winter season, respectively, and it can be defined as at top gear 60 krn./hr. in the summer season, 50 km./hr. in the spring and autumn season, and at 40 km./ hr. in the winter season.

As the present invention is constructed as described above, when the engine starts, the water pump rotates by pulley 1, but the cooling fan runs idly. When the ternperature of the cooling water of the engine reaches to the normal operating temperature (about 80 C.) which it does more quickly because the cooling fan is idle, the wax in the thermostat 5 melts and the volumetric expansion thereof elongates the movable pin to the left. Said pin pushes the push rod 18 to the left through the strong compression spring 17 against the spring 20. The end of the push rod 18 penetrates into the elastic body 19, thus pushed elastic body pushes the sliding block 21 radially outward against the relatively weak springs 28. Accordingly, the roller 22 at the end of the sliding block 21 engages with the cam ring 39, thus the cooling fan begins the rotate. Following the rise of the water temperature, the roller 22 engages with the cam ring 39 more strongly (see FIG. 3). When the revolution of engine reaches the predetermined value (assume the 50 ktn/hr. at top gear), the Weights 40, 40 are moved outwardly by the centrifugal force against the spring 46 (see FIG. 5). Accordingly, sliding pins 42, 42 are released and become free slidable outwardly and at the same time the sliding block 21 is pushed radially inwardly by the springs 28. As a result the roller 22 and the cam ring 32 are 'l disengaged (see FIG. 2) and the cooling fan runs idly. When the rotation of the engine comes down below the predetermined value, weights 40, 40' push down the sliding pins 42, 42', so that the sliding member 21 is pushed out outwards by the elastic body 19 thereby the roller 22 and the cam ring 39 are engaged (see FIG. 3) and the cooling fan is driven.

Even in the high rotational speed of the engine over the predetermined value, when the running speed of the automobile is low (for example in the case of driving on the long upward slope with reduced automobiles speed), the movable pin 1S of the thermostat moves to the left and the push rod 18 penetrates in the elastic body 19 more deeply. Accordingly, the sliding block 21 is moved radially outward thereby the roller 22 and the cam ring 39 engage and the cooling fan is driven.

`Further when the cooling fan runs over the predetermined revolution, the efiiciency thereof is reduced, so that it results in loss of the power. Action of the spring 17 suppresses the revolution of the cooling fan within the predetermined value. Namely, when the revolution of the fan 3S is over the predetermined value (say 2,500 r.p.m.), its driving resistance is increased and the spring 17 kept in equilibrium relation therewith is compressed through the elastic body, so that the roller 22 is pushed radially inwards, contact between the roller 22 and the cam ring 39 cornes out resulting in drop of the revolutions of the fan. When the revolution of the fan drops the resistance present by the fan is reduced, so that the sliding block 21 is pushed outwards through the elastic body by the repulsion of the spring 17. When the sliding block 21 engages again with the cam ring 31, the fan begins to rotate. As far as rotational speeds of the engine over the predetermined rotational value of the cooling fan, the

4 above action is repeated and the fan keeps a rotation of 2,500 r.p.rn.

Commonly in the long distance run over 50 km./hr., `amount of air flowing into the radiator is enough to cool the engine, -but the amount of this cooling air should be increased in the summer season and may be reduced in the winter season.

According to the present invention, very rational automatic engagement and disengagement of the cooling fan of an automobile engine can be effected. Simply by moving the spring supporting pins 47, 47 to the recesses for summer season, for spring or autumn season, for Winder season of the cam grooves 48, 48 of the weights 40, 40. Further, 52 denotes the screw for adjusting the working point screwed in the stopper plug 30. 53 is the locknut thereof. 54 is the recess provided in the elastic body for engaging the end of the adjusting screw 52.

As described above, the apparatus for engaging and disengaging the radiator cooling fan according to the present invention works in combination of the temperature of cooling water of the engine and the rotational speed of the engine and further it can be regulated according to season and drives the fan at the least limit required, so that the cost of fuel is greatly saved and the accelerating performance of the automobile is increased, and when the engine rotates at high speed the fan runs idly, so that there is no noise. The foregoing features are a great advantage in the automobile industry.

Further, when the cam ring 39 in the apparatus of this invention is made of synthetic resin such as Teflon or the like in place of metal, the frictional sound with the roller 22 can be reduced.

FIG. ll shows the other embodiment of the apparatus of this invention, in which the centrifugal force means in FIG. l is deleted and simplified in construction.

Though the invention is described by means of the embodiments as shown in the drawings, yet various modifications can of course be made without departing from the scope of the claims.

What I claim is:

1.. A clutch Iarrangement for the cooling fan of an automotive engine comprising in combination with a water pump having a casing and an impeller rotatably mounted in said casing on a driven shaft; a cooling fan freely rotatably mounted on said shaft, -a disc attached to said fan, a 'cam ring secured to said disc so as to -cover a portion of said shaft, a sliding block mounted on said driven shaft slidably in the radial direction therefrom, one end of said sliding block engaging with said cam ring, a thermostat mounted in said water pump to be actuated according to the temperature of the water flowing through said water pump, a movable pin actuated by said thermostat, a push- .rod connected to said movable pin, an elastic body fitted into a chamber within the driving shaft, said pushrod engagmglsaid elastic body, an axial movement of said pushrod being transmitted to said sliding block through the elastic body, said sliding block moving in a radial directlon of the driving shaft of the water-pump and one end thereof engaging said cam ring thereby engaging and disengagmg the cooling fan according to the water temperature.

2. A radiator cooling fan clutch for radiator cooling fans of automotive engines comprising in combination with a water pump, comprising a casing, a driving shaft, and an impeller rotatably mounted within said casing on said driving shaft, a cooling fan rotatably mounted on said driving shaft, a disc mounted on said cooling fan, a cam ring .secured to said disc so as to cover a portion of said driving shaft, a sliding block mounted on said driving shaft slidable in the radial direction, one end of said sliding block engaging with said cam ring, a thermostat mounted 1n said water pump, a movable pin actuated by said thermostat corresponding to the temperature of the water fiowing in the Water pump, a pushrod connected to said movable pin, an elastic body substantially filling a cavity within said driving shaft, one end of said pushrod engaging with said elastic body, a connecting member mounted on said driving shaft, a weight movable by the centrifugal force of the driven shaft pivotally mounted on said connecting member, a sliding pin having one end engaged with said weight and t-he other end engaged with said elastic body, an axial movement of said pushrod being transmitted to the sliding lblock through the elastic body, said sliding block moving in a radial direction of the driving shaft and one end thereof engaging with said cam ring thereby engaging and disengaging the cooling -fan `corresponding to the water temperature and when the rotational speed of the engine becomes greater than the predetermined value, said weight pivoting outwardly causing said sliding .pin to disengage fr-om said elastic member to reduce the force thereon thereby causing said sliding block to disenga'ge from said `cam so that said fan runs idly.

3. A cooling fan clutch device laccording to claim 1 in which a compression spring is mounted to oppose movement of said pushrod away from said elastic body thereby regulating the maximum revolution of the cooling fan.

4. A cooling fan clutch according to claim 2 in which a compression spring is interposed between the movable pin and the pushrod thereby regulating the maximum revolution of the cooling fan.

5. A coolingfan clutch according to claim 1 wherein the thermostat is a wax type, a boss pressed in the irnpeller of said waterpump by an O-ring and a stop ring, said -boss being fixed to one end of the driving shaft, said thermostat ybeing secured to said boss so that a heat sensible portion thereof is exposed to the water pass-age of the pump.

`6. A cooling fan clutch according to claim 1 in which a guiding groove is provided in the driving shaft, said sliding block being mounted in said guiding groove, a relief groove formed in said driving shaft at a right angle relative to said guiding groove, a spring receiving pin mounted in said sliding block and engaging in said guiding groove, a ixed spring receiving pin mounted in the side face of the driving shaft opposite said groove, and a tension spring mounted between said pins.

7. A radiator cooling fan clutch according to claim 2 in which a stopper plug closes said cavity, an andjusting screw mounted in said stopper plug and engaging said elastic body, said screw adjusting the .compression on said elastic tbody.

8. A cooling fan clutch according to claim 1, in which a recess is lformed in the elastic body, a leg of said sliding block engaging in said recess.

9. A cooling fan clutch according to claim 2 in which a first recess is formed in said elastic body to engage the leg of the sliding block, a second recess is formed in said elastic body to engage the end of the sliding pin and a third recess is formed in said elastic body to engage the end of the adjusting screw.

10. A cooling fan clutch according to claim 2 in which a recess formed in said elastic body to engage the end of said sliding pin is formed as an inclined cam groove against the weight actuated by the centrifugal force.

References Cited by the Examiner UNITED STATES PATENTS 2,838,244 6/1958l Oldberg 236-35 3,019,875 2/1962 Fowler 123`41.12 X 3,135,370 6/1964 Sutton 123-41.l2 X

KARL J. ALBRECHT, Primary Examiner. 

1. A CLUTCH ARRANGEMENT FOR THE COOLING FAN OF AN AUTOMOTIVE ENGINE COMPRISING IN COMBINATION WITH A WATER PUMP HAVING A CASING AND AN IMPELLER ROTATABLY MOUNTED IN SAID CASING ON A DRIVEN SHAFT; A COOLING FAN FREELY ROTATABLY MOUNTED ON SAID SHAFT, A DISC ATTACHED TO SAID FAN, A CAM BEING SECURED TO SAID DISC SO AS TO COVER A PORTION OF SAID SHAFT, A SLIDING BLOCK MOUNTED ON SAID DRIVEN SHAFT SLIDABLY IN THE RADIAL DIRECTION THEREFROM, ONE END OF SAID SLIDING BLOCK ENGAGING WITH SAID CAM RING, A THERMOSTAT MOUNTED IN SAID WATER PUMP TO BE ACTUATED ACCORDING TO THE TEMPERATURE OF THE WATER FLOWING THROUGH SAID WATER PUMP, A MOVABLE PIN ACTUATED BY SAID THERMOSTAT, A PUSHROD CONNECTED TO SAID MOVABLE PIN, AN ELASTIC BODY FITTED INTO A CHAMBER WITHIN THE DRIVING SHAFT, SAID PUSHROD ENGAGING SAID ELASTIC BODY, AN AXIAL MOVEMENT OF SAID PUSHROD BEING TRANSMITTED TO SAID SLIDING BLOCK THROUGH THE ELASTIC BODY, SAID SLIDING BLOCK MOVING IN A RADIAL DIRECTION OF THE DRIVING SHAFT OF THE WATER-PUMP AND ONE END THEREOF ENGAGING SAID CAM RING THEREBY ENGAGING AND DISENGAGING THE COOLING FAN ACCORDING TO THE WATER TEMPERATURE. 